The present invention relates to vehicles of small size, such as a motorcycle or the like, which may be provided with an engine between longitudinally spaced front and rear wheels and with a damper which is positioned between the vehicle body frame and the rear fork, the latter being swingably supported at its front end on the vehicle body frame and has the rear wheel rotatably supported by a shaft at its rear end. More particularly, the present invention relates to a rear wheel suspension device used in such small sized vehicles.
Shown in FIG. 1 is a known rear wheel suspension device for a motorcycle; for example, as described in Japanese Patent Laid-Open No. 60-163782 (No. 163782/1985). In this device, a rear fork 01 is swingably supported on the vehicle body frame 02 by a shaft at the point P. A rear wheel RW is rotatably supported by a shaft at the rear end of the rear fork 01. At the front end portion of the rear fork 01 is connected the lower end of a damper 04 through the intermediary of a well known progressive link mechanism 03. The upper end of the damper 04 is swingably connected to a bracket 06 attached to the rear end of a main pipe 05.
In such a structure which connects the damper 04 to the bracket 06 of the vehicle body frame, a large bending moment acts on the bracket 06 itself and on the main pipe 05. For this reason, these members must be provided with great strength and rigidity and therefore, such a structure results in a vehicle body of increased weight as well as of increased manufacturing cost due to the need to provide a support member having a large diameter and increased wall thickness. It is to the amelioration of this problem, therefore, to which the present invention is directed.